1. Field of the Invention:
This invention relates to a composite material composition using wastepaper obtained by first crushing wastepaper with no pretreatment and then mixing it with a thermoplastic resin, and a method of producing such composition.
2. Description of Prior Art:
Heretofore, synthetic resins either added or non-added with an inorganic filler or woodmeal and compressed boards using regenerated wastepaper have been available as boarding material for interior parts of automobiles.
However, synthetic resin moldings are generally unsuited for use as interior parts of automobiles because of poor heat resistance and flame retardancy.
The woodmeal-incorporated synthetic resins had problems in mechanical strength such as tensile strength, bending modulus of elasticity, bending strength and impact strength.
In the case of synthetic resins added with an inorganic filler such as talc, calcium carbonate, etc., for improving said defective properties of said single synthetic resins or woodmeal-incorporated synthetic resins, although heat resistance and flame retardancy as well as mechanical strength are improved, linear shrinkage in molding of such resins (0.8-1.5%) is not much different from that of the normal synthetic resins (1-2%), so that the molded parts therefrom, particularly those exceeding 1,000 mm in length such as for example front boards for automobiles, are elevated in dimensional tolerance to discommode mating or combined use of moldings.
As for the compressed boards utilizing regenerated wastepaper, they are variable in water content as they absorb moisture in the air, and they are also subject to extention or shrinkage in accordance with change of water content, resulting in irregular deformations such as warp or torsion. Further, such compressed boards, as compared with synthetic resins, have a certain limitation in bending or drawing work and are unable to make the moldings with an intricate configuration.
Generally, such compressed boards have been produced by first beating wastepaper in water, subjecting the beaten wastepaper to a paper-making process, drying the thus processed wastepaper and then subjecting dried wastepaper to compression molding. According to this method, large-sized equipments must be prepared for performing such beating, paper processing and drying, and naturally high equipment costs are required therefor. Also, a large volume of industrial water is required for beating and paper processing of wastepaper, and this necessitates an anti-pollution for treating waste water released from said processes.